Work out how a funding round changes who owns a startup, before and after the new money and option pool.
Enter the pre-money valuation, the amount raised and the option pool the investors ask for. The calculator shows the post-money valuation, the price per share and each group's ownership after the round, including when the pool is created before the round, as term sheets often require.
| Holder | Shares | Before | After |
|---|
A simple priced round with one class of new shares. Convertible notes and SAFEs that convert in the round, liquidation preferences and anti-dilution terms change the result and are not modelled. This is general information, not investment or legal advice.
How dilution works
New investors buy newly issued shares, so everyone who already owns shares ends up with a smaller percentage of a larger company. Their stake is the amount invested divided by the post-money valuation: $5 million into a company valued at $20 million before the round buys 20% of a $25 million company. Existing holders shrink by the same proportion.
The option pool is where the terms matter. When investors ask for a pool that must exist before their money comes in, the new options are counted in the pre-money valuation, so only the existing shareholders are diluted by them. Switch the setting above to see the difference. Our explainer on what a funding round does not tell you covers the other terms, and the tech funding tracker lists 2026 rounds as the companies announced them.
Questions
How do you calculate dilution from a funding round?
Divide the amount raised by the post-money valuation (pre-money plus the new money) to get the new investors' stake. Each existing holder's new percentage is their old percentage multiplied by one minus that stake, before any option pool changes.
What is a pre-money option pool?
An option pool created before the round and counted inside the pre-money valuation. It lowers the price per share, so the new investors are not diluted by the pool; the founders and earlier holders absorb it.